1.) Field of the Invention
The present invention relates to a carrying device for supporting a charge in a reheating furnace.
In particular, the invention relates to a carrying device for supporting a charge of slabs, billets, ingots and the like in a reheating furnace, with
at least one tubular support through which coolant flows, PA1 at least one high-temperature-resistant rider which has a top section and a bottom sections the bottom section of the rider being mounted on the tubular support and the top section forming at least one support surface to support the charge, and PA1 heat insulation means arranged on the bottom section of the rider. PA1 The bottom section of the rider has sides which are inclined towards each other such that the bottom section, seen in cross-section, forms a trapeze which tapers in the direction of the top section of the rider; PA1 the top section of the rider protrudes over each side of the bottom section forming a step; PA1 at least one supporting cam is arranged on each side of the bottom section, said supporting cam exhibiting a top surface which slants downwards in the direction of the relevant side; and PA1 the heat insulation means is designed as plate-shaped elements which cover the sides of the bottom section of the rider and are provided with recesses for complementary engagement of the supporting cams. PA1 the bottom section has sides which are inclined towards each other, the bottom section, seen in cross-section, forms a trapezoid which tapers in the direction of the top section of the rider, PA1 the top section of the rider protrudes forming a step over the sides of the bottom section; PA1 at least one supporting cam is arranged on each side of the bottom section, said supporting cam exhibiting a top surface which slants downwards in the direction of the relevant side.
Such carrying devices are preferably used in pusher-type and walking-beam furnaces which are upstream of a rolling mill. A major problem is to heat the charge as evenly as possible as only an even temperature of the charge guarantees uniform shaping in the downstream rolling mill. The quality of the final product is largely determined by the uniformity of shaping.
The critical points for the heating of the charge are the points where the charge is supported on the riders of the carrying device. As the bottom sections of the riders are mounted on the cooled tubular supports, heat automatically dissipates from these points. In particular, the bottom sections of the riders mounted on the tubular supports contribute towards generating cold charge areas in the charge.
2.) Prior Art
A carrying device of the aforementioned type is known from the U.S. Pat. Ser. No. 4,689,009 in which legs are attached to the sides of the top and bottom sections, partially encompassing the tubular support at a distance. Insulating material is packed in the cavities between the legs and the tubular support. However, the life of this insulating material is relatively short as the rider unavoidably moves against the tubular support due to thermal and mechanical stresses. Therefore, the shielding effect of the known design is only short-lived.